1. Field of the Invention
The invention concerns a method and apparatus for connecting two waterborne vessels together to create a composite vessel. More specifically, the invention relates to a method and apparatus for effecting a releasable, self-locking connection between a tugboat and a barge.
2. Description of the Prior Art
In the past it has been known to form a composite, waterborne vessel by connecting a tugboat with a barge. Typically, the barge used in such combinations is provided with a slot in the stern portion thereof which receives the bow of the corresponding tugboat. A mechanical connection between the tugboat and the barge has been generally employed to securely and releasably join the two vessels into the composite structure.
The use of conventional bollards in combination with suitable lines and quick release means to connect a tugboat and a barge is known in the art. Such connecting apparatus, however, is fraught with problems which inhibit its usefulness. For example, the tugboat must be properly aligned with a slot prior to entry thereinto. In addition, the requisite lines are susceptible to failure in rough seas, thus creating a potential for disengagement between the two vessels. Further, a connection system employing cables conventionally requires personnel on both vessels cooperating with one another properly to position and tension the cables.
It is also known to employ hydraulically operated members carried by a tugboat to facilitate the connection of the tugboat to a barge. Such hydraulically operated apparatus, however, is typically provided to wedge the tugboat and barge together thereby retaining the two vessels in their composite relationship even in the face of rough seas. Leakage of hydraulic fluid or loss of hydraulic pressure presents a potentially severe problem in that it may allow loss of latching force between the two vessels. Another common problem with hydraulic wedging apparatus resides in the fact that the vessels must be properly aligned before the hydraulically actuated members can be effective to secure and position the two vessels relative to one another. As with the wedging mechanisms, however, the loss of hydraulic pressure, leakage of hydraulic fluid or misalignment of the vessels may present intolerable problems.
It is also known to employ threaded-type connections between two vessels. Such connections, however, are cumbersome, require previous alignment between the two vessels and do not permit the use of rapidly actuated members.